Cartridge for hypodermic syringes



' Dec. 23, 1941. w, Roc w 2,267,074

CARTRIDGE FOR HYPODERMIC SYRINGES Filed April 30, 1940 INVENTOR W4 LAEDH B/wc/rn/A y H I ATTORNEYS Patented Dec. 23, i941 CARTRIDGE FORHYPODERMIC SYRINGES Willard H. Brockway, Needham, Mass.

Application April 30, 1940, Serial No. 332,493

4 Claims.

My present invention relates to an improvement in cartridges and likeunits, and more particularly to such units filled or to be filled with afluid medicament intended for hypodermic administration. Such units areusually used in a suitable hand operated syringe such as I showed anddescribed in my prior Letters Patent No. 1,604,018, granted to meOctober 19, 1926, and which has become a standard type and one quitegenerally in use by dentists or dental surgeons.

The pain deadening solutions as in procaine, morphia or opiate solutionsused in dental surgery olIer particular problems and particularly thosein which the pH. value has to be insured by so-called buiiering. As thisprocess renders the solution subject to deterioration with age, it hasbeen necessary heretofore to date each such unit and instruct its usewithin a definite time. This was, of course, inconvenient and subjectedthe surgical profession to an additional responsibility and anxiety asto results in cases where it is found necessary to give such treatment.

My concept involves a radical departure in the basis of handling suchsolutions as well as a certain improvement in such unit structureseffective of increase in convenience, strength, safety and generalutility.

As illustrative of my invention and improvement I have selected a formin which I have embodied my concept in a unit of what might be called agenerally standard or conventional type. As its general aspects andtechnique in use are familiar to the profession, such an embodimentoffers many immediate advantages. To this I have added suggestivemodifications.

In the drawing I have illustrated a simple form ofiny improvement whichwill be hereinafter described and which is set forth as follows:

Fig. 1 is a general view of one of my units shown in combination withone of my syringes, the parts being broken out centrally for the purposeof shortening the view, and

Fig. 2 is a longitudinal section of a unit in accordance with myinvention.

Fig. 3 is a view of the plunger-stopper construction and its primer orsecondary container.

Fig. 4 is a view of the plunger-stopper construction with a modifiedprimary and secondary container.

Referring to Fig. 1 I have indicated my cartrldge imit generally as Tloaded in the frame I of one of my standard types of syringes. In thisit is held at one end by a head cap 5 pivoted to the frame as at l andat its opposite end by a cap 2 to which the needle 3 is attached by aclamp 4. In such an instance, the needle 3 would be of a double endedtype.

As shown in Fig. 2, the cartridge unit consists of the tube T which hasan inturned lip t forming a shoulder about its end opening. Against thisshoulder t is lodged internally of the tube end, an end seal consistingof a plug 2| having an exterior annular shoulder 22 and a central discor button 23. As the disc or button 23 is resilient, the parts of theplub 2| being of rubber or like resilient material, it is readilycompressible and thus easily lodged and locked in the end of the tube T.The outer end of the central disc or button 23 projects slightly beyondthe outer face of the lip t so as to make a resilient cushion for thisend of the cartridge both in packing and in clamping in the syringeframe in which it bears against the inner face of the end cap 2. Byrewon of its shoulder 22 and the opposed lip t any expulsive tendency byplunger or pressure of the fluid charge S is done away with. The plug 2|is provided with a cavity 24 which reduces the effective thicknessaxially through the button 23 so that the inner end of the double endedneedle 3 which penetrates the plug does not have to pierce through itswhole length.

At its opposite end the tube T is closed by a frictionally fittingplunger-stopper or cork C. This is preferably provided with externalgroove rings c to increase its efllciency as a piston when it is pusheddown by the plunger 9 to expel the charge S when an injection is beingmade.

This plunger-stopper of cork C is furthermore, as shown in Fig. 2,provided in its outer portion with an axial pocket 30 preferably ofcylindrical bore. In the form shown in this figure, the pocket 30terminates just short of the innerend of the plunger-stopper or cork Cleaving a wall or diaphragm 3|.

Frictionally lodged in the pocket 30 is a priming quill or secondarycontainer 40 having a closed outer end and an open inner end ll. Thepriming quill or secondary container shown is made conveniently as a cupof non-corrodable metal.

In the form oi secondary container shown in Fig. 3, I provide aplunger-stopper or cork 0 provided with an axial pocket as at 52terminating just short of its inner end as in Fig. 2, but leaving asomewhat thinner wall or diaphragm 5|. I form my secondary containerwith a retaining ring 53 which is seated in a corresponding re- (265$ 54in the pocket 52.

In this form the container ill is held against movement and isdischarged by heating the exposed outer end of 5| which generates aninternal pressure and ruptures the thin diaphragm 5| thus discharginginto the primary charge of the cartridge;

In another modification, illustrated in Fig. 4, the container 50' has noretaining ring and is held against movement simply by knurling orroughing up its surface so that it will be frictionally engaged in theaxial pocket 52. It will then stay putwhen heat is applied to the outerend.

In operation, after the container 50 has been discharged, the unit T isclamped in the frame I of the surgeon's syringe being held thereinbetween the head 8 or, more strictly speaking in the form of syringeshown, by the block I2 resiliently urged by the spring I0 and with itslower end seated in the cap I as before described. This spring III alsofunctions as a frictional control on the plunger stem 9 so that the,outer end of the secondary container lli is, therefore, up to thistime, not subjected to any pressure from the plunger head 9 a When,however, the operator is ready to use the syringe so loaded, he pressesthe handle II with his working thumb so that the pressure first movesthe piston head 9 into contact with the end of the secondary container40 in the pocket 30 of the cork C.

The syringe is now ready for use and the operator after inserting thepoint of the needle 3 into the tissues at the desired locus, again findsthe handle II with his working thumb and carries through with theplunger pressure as desired. In this movement, the end face of theplunger head 9 contacts the outer end of 40 and thus carries the entirecork 0 along as an advance plunger or piston to discharge the nowbuffered or modified contents of the unit T.

It will be understood that the type of primary charge requiringbuffering is used by way of illustration and not as limiting, as variouscharges or solutions might be used and the secondary charge be providedfor its modification on a basis other than buifering. All suchmodifications in the form and use will be understood as within thespirit of my invention.

. This is a continuation in part of application Serial No. 48,726, filedNov. '1, 1935.

What I claim is:

1. A cartridge for use with a syringe consisting of a body member havinga primary chamber formed therein, a piston head closure member sealingone of the ends of the said body member, a secondary chamber formed inthe said piston head closure member and provided with an axial pocketterminating just short of the inner end of the piston head closuremember but leaving a thin diaphragm, and open at the outer end thereof,and a container lodged in said secondary chamber provided with means toretain it in fixed position relative to the piston head closure member,said container projecting at its outer end beyond the outer face of saidmember and being closed at said end, and provided with an opendull-edged inner end facing said diaphragm.

2. A cartridge in accordance with claim 1 in which the means to retainthe container lodged in the secondary chamber is a retaining ring seatedin a recess attached to said secondary chamber.

3. A cartridge in accordance with claim 1 in which the means to retainthe container lodged in the secondary chamber is a knurled surface ofthe container by which the container is frictionally engaged and held insaid secondary chamber.

4. A cartridge in accordance with claim 1 in which the means to retainthe container lodged in the secondary chamber is a roughed-up surface ofthe container by which the container is frictionally engaged and held insaid secondary chamber.

WILLARD H. BROCKWAY.

